China's self-developed unmanned autonomous underwater vehicle, Qianlong-2, has accomplished a lot in undersea exploration that wouldn't have been possible without the intelligence and huge efforts of the dedicated research team.

Moving vigorously in deep-sea water like a small yellow fish. Qian-long-2, the autonomous underwater vehicle, or AUV, is 3.5 meters long, 1.3 meters high, and 0.7 meters wide. It was independently designed by Chinese scientists, after eight years of hard work.

"The autonomous underwater vehicle has a very innovative design. We have to check and work with the command system over and over again. So the project team has worked overtime, from day to night, on weekdays and weekends," said Liu Jian, Chinese Academy of Science.

Laying, detecting, and retrieving are the three main tasks of the Qian-long 2's expedition. However, the vehicle's weight of over 1.5 tons made laying it on the crane a huge challenge. Strong winds put it at risk of a terrible crash at one point.

"It feels like you are holding a gun and targeting a bullseye when riding a horse. but the target keeps moving up and down," said Wang Xiaofei of Chinese Academy of Science.

"Although we are researchers, yet when we are on board, we still have to do a lot of physically demanding labour. We all have to pull the ropes to keep it from swaying," Liu Jian said.

Thanks to the dedication of the whole team, Qian Long-2 has so far achieved a lot in deep-sea exploration, growing from a concept to a smart deep-sea robot.

It has completed 16 diving missions, managing a maximum depth of 3,200 meters. It has explored  an area covering more than 218 square meters over the past five years.

Qian Long-2 has not only filled the gap for autonomous underwater devices in China, but has also marked a milestone in achievements for the country's deep-sea exploring technology.